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Forgot to mention that more TX power is going to require more isolation on the RX input side. A few people have experienced RX desense with the power being too high. They did what would at first appear to be counter intuitive, they decreased the TX power.

If you're focused on getting 'max power' out for Transmit, then I need to ask, what are you talking to on the other end? If you've got 4 or 5 watt portables, transmitting at 25 watts (and setting aside any antenna system gain/loss for a moment) creates an imbalanced system at best - and generates a bunch of unnecessary interference to your own receiver at worst. In other words, if you can transmit out 15 miles, but your portables can only talk back in from 5 miles, what have you accomplished? Balance to the system is the key. As gortex mentioned, filtering the receive side is probably more important, but most advertising will focus on the 'horsepower' number, because that's what sells. Any rookie will pick a 50 watt transmit over 25, because more MUST be better. It's just one number, and transmit power rarely tells the whole story, especially when it comes to repeater system performance. Losing 1.5 or 2 dB to gain 60 or 70 dB of isolation is a pretty good trade off, and if you put a bandpass cavity tuned to the receive frequency on the receive side of that cheap duplexer, you're going to pick up even more isolation without increasing any losses on the transmit side. I can tell you that my basic rule of thumb for a generic repeater is to shoot for double the power of the portables being used. You're well above that at 25 watts, and I'm not aware of too many low cost repeaters that will do an actual 100% duty cycle at 25 watts. There are plenty that will approach 100% duty at 10 watts with a good cooling fan. Until you've got a quality receiver with decent filtering on the receive side of the system, it really doesn't matter how much power your transmitter has. Isolation, selectivity, and sensitivity are all more important than raw transmit power when you're looking at a repeater system.

You can use this to get a good estimate https://extapps.commscope.com/calculators/qvisolation.aspx Keep in mind, even a cheaper mobile duplexer can achieve 70db isolation, better on decent mobile duplexers, and you will likely need greater than 60 feet vertical, one directly above the other, to get it working anywhere close to the performance of a duplexer.

what he said... I like Scotch 130C spicing tape (stretch it as you wrap it) it molds to itself and once it's on it's not coming off. If you really want to be sure it's sealed brush it with some Scotchkote after you tape it (but wear some latex gloves, it sticks to everything). No I don't have stock in 3M. Did I mention it's not coming off? So make sure to test everything first if you go this route.

Conspicuously lacking was the number of stickers seen (which was few, and a positive, non-zero and undisclosed number at the time of this posting). ?

It’s usually only the last foot or two that are ruined on the cable. You really can just re-terminate the cable. Another thing that helps is to liberally apply Vaseline onto the PL-259 and SO-239 before connecting them together. Still use the self vulcanizing tape.

Cut the beginning off and replace it! ?

I've had 3 different repeaters over the last two years: DIY 2 KG-1000Gs Retevis RT97 Vertex VXR-7000 All using the same ~$120 Tram 1486 base antenna and 75 feet of LMR400 coax The two KG-1000Gs was the most expensive (~$875) and had the most power - but it was also the most unwieldy and issue-prone The RT97 was a much more compact package, and was the least expensive (~$400), but only output about 4-5watts after the duplexer and has a limited duty-cycle The Vertex VXR-7000 (what I currently use) is by far the best solution. I paid $500 for mine (used), it puts out ~25 watts after the duplexer and it can be used 24/7 (100% duty cycle) - But because of its age its a bit of a pain to program/get set up. My recommendation, based on my experience, would be to try and get a good used commercial repeater (like the VXR-7000) OR an RT97. Next month another company will be releasing a new GMRS repeater very similar to the RT97 but easier to configure - but i'm not allowed to talk about that yet.. So you might want to wait and see if that one works better for your needs.

Well I guess I should have used smaller images... or just links. Sorry for the enormity of those ?

Ensure that the driver is properly communicating with the comm port that the cable is plugged in. The device manager will show that. If you can’t “read” the radio from the computer, try anothe usb port. Most of the time it is a driver issue.

I should have clarified that point. But they are digital modes. Sorry about that. We have 3 or 4 active but seldom used D-Star repeaters and 10 or so pretty active C4FM repeaters in my area. I probably should have got a Yaesu as it's more popular in my area but too late now.

As a great number of new users are joining every week with the same questions about tones and programming for repeaters, would it be possible to create a FAQ section with answers for these questions? More FAQs can be created for other common questions as needed if new users could be directed to that section.

What repeater ? What Radios ? What antenna ? What feedline ? Normally by the time you buy feed line to get the distance you spent more than a cheap duplexer. If you are doing sperate antennas you will need as much vertical separation as you can get. Most dual antenna systems use filtering on the RX side of the system to notch out the TX frequency.

I have a Radioddity DB20-G that works fine on Amateur 2 meter and 440, and GMRS. Done through chirp software

But I’d like to try and explain it in my words as well. The human ear has the ability to hear over a spread of frequencies from about 10-20 Hz on up to 15,000 Hz or even up to almost 20,000 Hz. High frequencies become more difficult to hear as you get older or suffer hearing loss. So that’s a bandwidth of say 20 Hz to 15,000 Hz or 14980 Hz. Speech can be pretty accurately reproduced in a much narrower bandwidth, but there’s still some information at the higher frequencies that help you discern different sounds, such as an ‘f’ sound from a “th” sound or even an ‘s’ sound. Now imagine if someone applied a band pass filter that starts at 300 Hz and ends at 6000 Hz. That’s narrowband. Compare that to a filter that allows 300-12500 Hz bandwidth. More sound information that can be encoded in that bandwidth. A wideband signal received by a narrowband receiver has to throw some of the information away, making the sound quality less, even though there’s more signal than it knows how to handle. A narrowband radio encodes less information but a wideband receiver receiving that information ends up a partially empty channel, which can sound weaker. But narrowband sounds okay when both ends are set to narrowband and wideband sounds incrementally better when both ends are set to wideband.

Good news that your noise is gone. I had this issue with a VHF/UHF radio installed in my Sienna, even after bonding everything. For those of you with chronic alternator whine, one way to tell where the noise is being fed into the radio is by removing the antenna from the radio. If the alternator noise persists, it may be coming in through the power leads, even if they are connected directly to the battery, which mine are. I ended up building a noise filter out of a Quick Link, 20 feet of 12 gauge stranded wire, and a 47k uf capacitor. It knocked out 99+% of the noise. Some will say my alternator is bad, but it's much cheaper to install a $20 filter than it is to drop $300 to replace a working alternator with a working alternator. Here's the link to the build: http://www.sanantoniohams.org/tips/whine.htm

What if the water entered the coax at the beginning? ?

It could be because of that but it could also be because moisture has entered your coax cables at the connectors. Unfortunately once that happens the best thing to do is cut the end off and replace it.

I work in Bellevue. I will try to hit repeater WRUB436 when I'm in range to test it out the next few days: Sunday, Dec 10th - 4:45a & 3:00p Monday, Dec 11th - 4:45a & 3:00p Tuesday, Dec 12th - 4:40a & 5:45p Wednesday, Dec 13th - 10:00a I'm new as well, and studying for my ham license (technician & general) to test in Sioux City in January unless the Aksarben club can test me. I might miss the times I listed above on Tuesday and Wednesday in the afternoon.

Not specifically referencing power limits, but this is wording I got in a response from the folks in charge, if it helps: Handheld portables are a subset of mobile stations and must comply with any applicable mobile station requirements and any additional requirements for handheld portable units.

That is sort of funny since they are not vanity plates. You have to provide your FCC license to get one, and at least here in Michigan, the cost is the same as a regular plate.

I put Kaf6045 on my "3rd-grade hall monitor block list" a long time ago so i dont know what he posted, but, It is important to know the rules.. It is also important to understand the risks and what happens in the real world.. The head of your GMRS group is correct, it is no more of an issue than rolling through a stop-sign is an issue, as the FCC, based on their published record of enforcement, does not care.

I didn't vote. I'm not one to put stickers on my vehicles, though and I really don't drive around with my radio on. I only use my GMRS radio when my kids are at our cabin or when I'm launching rockets with friends. I don't use GMRS the way I use ham radio, where I might sit at the radio an try to listen to distant stations or join in a local net. For me, although I'm interested in the technology and regulations, GMRS is just a way to communicate while enjoying other things.

Says: wrtq 652!!! ?

For troubleshooting, run the radio on a separate battery and see if the noise is gone. Also, if you unplug the antenna from the radio, is the noise gone? Without getting into a bunch of technical BS about capacitive and inductive coupling and introducing noise, mounting a mag mount on a plate that is sticky taped to the hood is likely contributing to your issue. I strongly recommend this type of lip mount. Also, if you absolutely insist on a bonding strap, go from the hinge bolt to the body like the points in the photo.

Hey folks. I have been helping someone here with questions about getting more power out of their radio and into the antenna. I thought the discussion could help many new people, so I am sharing some of that conversation here. This is a really long post. Sorry about that, but I think it's worth it. If you have any questions, just ask. I am sure myself or one of the other experienced operators or engineers can help. ----------------------------------------------------------------------- I think, to help make sense of power vs performance in GMRS, I'll explain how the signal strength is impacted by output wattage. UHF (where GMRS lives) is a Line of Sight service. This means exactly what it sounds like. If it's in the RF line of sight, you can talk to it. When we talk to radios on the surface of the earth, you can only talk to the visual horizon, plus about 15% (aka the Radio Horizon). The higher both antennas get, the further the horizon and the further you can talk. From the roof of a 15 story building, I can use 0.5w from my handheld to talk on a repeater over 50 miles away. I talk to satellites in orbit, 240+ miles above Earth, with only 0.25 watts because there is nothing but empty space between us. There is some very minor benefit to more power. One of the reasons why the GMRS radio waves can be heard past the visual horizon on earth is because some of the signal gets bent / refracted, as well as scattered in all directions while it travels, creating the referenced RF horizon. Some of this signal scatters back to earth while the rest travels out into space. It's a very small percentage and it varies depending on the atmospheric conditions. That said, if you have 100w out and only 1% of your signal gets scattered back to earth (example only), someone can hear that 1 watt and you may be able to talk if the other person's signal scatters about the same, coming back to you. Scatter is extremely unreliable, however. I'll explain why getting the antenna as high as possible is for the best, compared to adding more power. In the radio world we use a quality scale to define how well your signal is being heard. This is called the RST System. RST stands for Readability (how intelligible your words or information is), Signal Strength (how strong your signal is heard by the receiving station), and Tone (mostly used in Morse Code communications). For the voice side of things, we typically only use the RS portion. R is on a scale of 1 to 5, with 1 being aware that someone is transmitting voice, but can't make out anything. An R5 means, regardless of signal strength, your words are 100% intelligible. For the S, we use an S-meter and provide the total number of S-units read on the meter. This indicates how strong your signal is. This is a picture of an analog S-meter scale. The letter S on the left represents one (1) S-unit. The largest S-unit reading on s-meters is the 9 or S-9. I'll explain the +10, +30, +60 in a moment, So, just referencing the RST system and the meter above, the best signal report would be a 5/9 (pronounced five nine) or 59. This means your voice is completely understandable and your signal is strong enough that the needle moves to 9 s-units, the maximum value on the number scale (normally there is zero static or noise heard at this level). The commonly accepted minimum signal report that is considered "usable" is a 2/1, 2 for voice quality and 1 S-unit. However, that is absolute worst case, if it was an emergency and you can repeat information over and over to get the communications out. There is a tremendous amount of noise and your voice is barely being understood when it is heard. Conversational minimal signal reports are going to be about a 3/2, but that is still aggravating and most people give up quickly due to the static and missing every other word or every third word. It's mostly "call me on the phone" or "almost there" kind of stuff. And then there is what most people tolerate for chit-chat, and that is a 4/3. Meaning, I can hear everything you say. There is much less static, and the signal is strong enough that you have established reliable communications. So, to understand what an S-unit is and how it impacts the quality of communication, I have to explain what the meter is actually measuring. One s-unit is equal to 0.2 microvolts detected at the receiver antenna input. Regardless of how much power the transmitter is and regardless of how far that station is, if 0.2 microvolts makes it to your radio, that radio is hearing 1 s-unit of signal. Lets say you have 10w going into the transmit antenna and the receiving station is fairly far from your radio, only receiving 1 s-unit. 10w We really want to get to 3 s-units for reliable communications. Well, in order for the received voltage to climb 1 s-unit, you need to multiply your power by 4. That means to move 1 s-unit on the receiver, you need to increase your transmit power to 40 watts. 40w However, we already know that 2 s-units isn't really usable. To get to 3 s-units, you need to multiply your power 4 times, again. That's 160w into the antenna to go from "I know you're there" to "I can actually talk to you" (assuming your audio is good). 160w Lets assume you wanted to try to get the s-meter to swing to 9 s-units. Well, that will take 655,360 watts. 655,360w Now, the + scale is even more fun You need to double your power for every 3dB increase in measured power. You need go up 4 times the power to increase by 6dB. Those + readings are for strength in dB over the s-9 signal strength. Since in our specific example we know you need 655,360w to go from s-1 to s-9, to get to +30dB over s-9 you need to increase your transmit power to 655,360,000w. That's 655 million. Not a type-o. 655,360,000w So now, lets go back to the original limit of GMRS being a Line of Sight service. That 160w you needed to get to 3 s-units, basically netted you zero distance compared to the 10w, because the horizon didn't change. All you did was make it so that those who could hear you, now understand what you are saying... maybe. To make things even more bleak, if you are communicating due to scatter and 1% or less of your signal is being heard, the amount your transmit power would need to increase is unfathomable. And did I mention that all that transmit power did absolutely nothing for your receive capability? So, you can see why it's not practical to chase power output. If you get your antenna 30 or 40 feet higher, you would actually improve your communications range and quality of reception much more than if you can increased your power from 10w to legal limit.

Great question! If you have walls of a canyon that are high in iron and other conductive material, there can be some tunneling or directional impact, but its rare for it to be in high enough concentration to work. Most natural barriers, such as the trees and hills/mountains absorb UHF signals... however, UHF penetrates man-made structures, like buildings, much better. More power would be more beneficial in urban areas than in other types of areas. More power is going to be a benefit in rough terrain for other reasons, though. RF shadowing is like shadows from the Sun. There is never complete darkness behind a rock or mountain. Same with radio waves. Refraction and scatter places the radio waves behind stuff... the sharper the angle, the less scatter. So, the more power you have, the less you are going to be impacted by shadowing, but only to a limited degree. HF signals will bounce off of stuff pretty well, and goes through trees and foliage with no issues.

Great post! Is not more power also helpful in penetrating objects like walls, and bouncing the signal through canyons, etc, for example when off-roading?

I'm not an old Ham... but if you're talking to someone over the internet, that isn't radio, in my opinion. The whole point is to use airways to talk. If you are using the internet, you may as well be on a computer or smartphone. I especially feel this way about people using their smart phone to get into a group and they aren't even on a radio. If 2 people are using their smartphone to talk to each other though a Fusion or WiresX web app, how the heck is that Ham radio? If that counts, anyone who talks on a cell phone may as well consider themselves a Ham. LOL

I passed the Tech exam this morning by remote! I missed one question. Now it's time for some serious thought about which radio. That FT-991a is sure tempting but I may just start out simple with a dual-band unit.

There is a tremendous amount of benefits with Amateur Radio vs. GMRS. First, lets just talk about voice. On GMRS simplex, the absolute very best you can expect from a perfect setup, is going to be about 70 miles. Likely less. That would be mobile or base. With Amateur Radio VHF and UHF, the power limits are 1500 watts with no radiated power restrictions. That means with a little elevation, you are talking coast to coast on the higher portions of VHF and the lower portions of UHF. On the lower portions of VHF, you can talk to Europe, Mediterranean, Northern Africa, etc. Even in my mobile, I can talk to NY from Virginia on VHF simplex. With things other than voice... there is no limit to what you can do beyond no encryption. If you can dream it, you can do it on amateur radio. There is APRS, which provides transceiver location services. There FLDigi which is used for texting and simple messaging. There is WinLink which is a 100% radio-based email service that allows you to email other operators as well as people on the public internet. And much, much more. The benefit of HF and MF is, the ease of global comms as you drop in frequency. I was driving around in my Jeep today on an HF frequency that Tech license holders have access to. I talked to people in 3 different countries on 2 different continents with a simple 100 watt mobile radio and a whip antenna. It's really a lot of fun. As far as a base station goes, I don't use mobile radios for base a station. I have base station radios that I use for VHF, and a VHF/UHF repeater. I talk on VHF on the base for several hours a week, sitting in my executive desk chair. As far as the quality of conversation... I can't really say much about that. I would assume there are plenty of people to talk to without getting into religion, politics, etc. I avoid them like the plague. With regard to if it's worth it... that is a personal choice that each person needs to decide for themselves. I think it is. I held my Tech license for 17+ years before I got my General and had a great time. I also think the GMRS and FRS are great radio service and fill a nice niche.